Ann Agric Environ Med. 2013; Special Issue 1: 23–27 ORIGINAL ARTICLE www.aaem.pl

Psychological Aspects of Pain Rafał Gorczyca1, Rafał Filip2, Ewa Walczak2 1 Department of Public Health, Institute of Rural Health, Lublin, Poland 2 Department of Clinical Endoscopy, Institute of Rural Health, Lublin, Poland Gorczyca R, Filip R, Walczak E. Psychological Aspects of Pain. Ann Agric Environ Med. 2013; Special Issue: 23–27. Abstract Introduction. Pain is defined “an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage”. Pain is a sensation of the body, and is always an unpleasant emotional experience. The role of psychology is auxiliary and supplemental to medicine. This is an aid addressed to the patient, physician and patient’s caregivers: professional caregivers, family members and significant others. At each stage of the diagnostic and therapeutic process, psychology offers help, both from the cognitive and practical aspects. Objective. The objective of the article is to present important psychological aspects of studies concerning pain, and the psychological methods and techniques of pain treatment. State of knowledge. Pain is the leading reason for patients seeking medical care and is one of the most disabling, burdensome, and costly conditions. Pain accompanies many diseases, each one of which generates unique/separate diagnostic, therapeutic and research problems. Depression and related psychical disorders. There is a significant relationship between depression and pain symptoms, as well as between pain and suicidal thoughts. Patients with a long history of pain disorders also have increased depression and anxiety symptoms, as well as suicidal thoughts. Patients with more severe depression and anxiety symptoms also have an increase in pain problems. The intensity of pain correlates with the intensity of psychopathological symptoms – both with mood lowering and with anxiety symptoms and worry. Active pain coping strategies strive to function in spite of pain, or to distract oneself from pain, are associated with adaptive functioning. Passive strategies involve withdrawal or relinquishing control to an external force or agent and are related to greater pain and depression. Pain catastrophizing is a negatively distorted perception of pain as awful, horrible and unbearable. Catastrophizing is strongly associated with depression and pain. Studies in which functional magnetic resonance imaging (fMRI) was used showed that pain catastrophizing, independent of the influence of depression, was significantly associated with increased activity in brain areas related to anticipation of pain, attention to pain, emotional aspects of pain and motor control. Pain behaviour is a conditioned pain. Care and concern on the part of others, secondarily enhance a patient’s pain behaviours, which lead to an increase in the intensity of the pain experienced. A history of early life adversity (ELA) – rejection, neglect, physical or sexual abuse is related to the development of irritable bowel syndrome (IBS) in adulthood. Ovarian hormones have been shown to modulate pain sensitivity. Imaging of the human brain in chronic pain. Acute pain and chronic pain are encoded in different regions of the brain. Chronic pain can be considered a driving force that carves cortical anatomy and physiology, creating the chronic pain brain/ mind state. Cognitive-behavioural methods of pain treatment in domains of pain experience, cognitive coping and appraisal (positive coping measures), and reduced pain experience are effective in reducing pain in patients. Key words pain, coping, cognitive-behavioural therapy

INTRODUCTION usual sensory qualities of pain. Many people report pain in the absence of tissue damage or any likely pathophysiological Pain is defined by the International Association for the Study cause; usually this happens for psychological reasons. There of Pain (IASP), as “an unpleasant sensory and emotional is usually no way to distinguish their experience from that experience associated with actual or potential tissue damage, due to tissue damage if we take the subjective report. If they or described in terms of such damage” [1]. regard their experience as pain, and if they report it in the In note to the definition, authors clearly pointed out, that: same ways as pain caused by tissue damage, it should be pain is always subjective, it is that experience we associate accepted as pain. Activity induced in the nociceptor and with actual or potential tissue damage. It is unquestionably nociceptive pathways by a noxious stimulus is not pain, a sensation in a part or parts of the body, but it is also always which is always a psychological state, even though we may unpleasant and therefore also an emotional experience. well appreciate that pain most often has a proximate physical Experiences which resemble pain but are not unpleasant, e.g., cause [1]. pricking, should not be called pain. Unpleasant abnormal The theory of pain published in 1965 by Wall and Melzack experiences (dysesthesias) may also be pain but are not was of crucial importance for the understanding of the pain necessarily so because, subjectively, they may not have the phenomenon [2]. In the light of this theory, the experience of pain is a multidimensional phenomenon that is influenced Address for correspondence: Rafał Gorczyca, Institute of Rural Health, Department of Endoscopy, Lublin, Poland by multiple factors, such as affect, previous experience and e-mail: [email protected] cultural beliefs, in addition to sensory input [2]. It provided Received: 09 December 2013; accepted: 29 December 2013 an impulse for a wider consideration of psychosocial factors 24 Ann Agric Environ Med. 2013; Special Issue 1 Rafał Gorczyca, Rafał Filip, Ewa Walczak. Psychological Aspects of Pain in the studies of pain, and being subject to modifications and occurrence of musculoskeletal pain, headache and pain in the supplementations in the course of progress in knowledge, it chest within the subsequent 3 years [10, 11, 12]. Apart from has stood the test of time [3]. severe depression, pain may also accompany other mood Pain, as mentioned, is a psychological concept; however, disorders: small depression, dysthymia, bipolar affective the basic tasks: diagnosis of the causes of pain in an individual disorder, depression caused by somatic diseases or drugs, or patient, planning of the implementation of an appropriate an incomplete remission in a severe depression [13]. therapy, belong to the physician. The role of psychology is In the studies by Wasilewski it was found that the intensity auxiliary and supplemental. This is an assistance addressed of pain correlates with the intensity of psychopathological to a patient, physician, a patient’s caregivers: professional symptoms — both with mood lowering and with anxiety caregivers, family members and significant others. At each symptoms and worry. The stronger the pain, the worse the stage of the diagnostic and therapeutic process, psychology psychical status. With growing intensity of pain, patients offers help, both from the cognitive and practical aspects. more frequently had suicidal thoughts, and their intensity was higher [6]. In the MMPI test, individuals who suffered from Objective. The objective of the article is the presentation chronic pain usually have high indicators of hypochondria, of important aspects of studies concerning psychological depression and hysteria. conditioning of pain and psychological strategies and techniques supporting patients in their struggle with pain. Maladaptive coping strategies and beliefs. Coping is an effort to manage events that are perceived as stressful. Active State of knowledge. Pain is the leading reason for patients coping strategies strive to function in spite of pain, or to seeking medical care and is one of the most disabling, distract oneself from pain, are associated with adaptive burdensome, and costly conditions in the USA [4, 5]. Pain functioning. Passive strategies involve withdrawal or accompanies many diseases. In American studies [4] the relinquishing control to an external force or agent are related following list of diseases has been considered, recognized to greater pain and depression [14]. as generating the greatest pain problems (in alphabetical order): 1) Ankylosing spondylitis, 2) Cancer pain, 3) Cervical Cognitive errors – pain catastrophizing. A cognitive radiculopathy, 4) Complex regional pain syndrome, 5) error may be defined as a negatively distorted belief about Diabetic neuropathy, 6) Fibromyalgia, 7) HIV-associated oneself or one’s situation Such errors are hypothesized pain, 8) Interstitial cystitis, 9) Irritable bowel syndrome, 10) to influence the severity and maintenance of depression Low back pain, 11) Lumbar radiculopathy, 12) Migraine, and include catastrophizing (misinterpreting an event as a 13) Multiple sclerosis associated pain, 14) Osteoarthritis, catastrophe), personalization (taking personal responsibility 15) Painful bladder syndrome, 16) Phantom limb, 17) for negative events), and selective abstraction (selectively Postherpetic neuropathy, 18) Psoriatic arthropathy, 19) attending to the negative aspects of a situation), among Rheumatoid arthritis, 20) Spinal cord injury, 21) Stroke others [15]. Pain catastrophizing is a perception of pain associated pain, 22) Surgically-induced pain, and 23) as awful, horrible and unbearable. Catastrophizing is also Trigeminal neuralgia. strongly associated with depression. It is also an important Each of the above-mentioned diseases generates unique/ factor in the experience of pain. Among patients with soft- separate problems from the aspect of loading a patient with tissue injuries catastrophizing significantly correlated with the disease, costs of health care, and diversity of concomitant patient’s reported pain intensity, perceived disability and diseases. Also, each of them constitutes a separate area of employment status. independent of the levels of depression diagnostic, therapeutic and research problems [4]. and anxiety [13]. Studies in which functional magnetic resonance imaging (fMRI) was used showed that pain Depression and related psychical disorders. A sensitive catastrophizing, independent of the influence of depression, early symptom of depression are pain disorders [6]. was significantly associated with increased activity in Relationships between depression and pain may be of a two- brain areas related to anticipation of pain (medial frontal way character [6]. There is significant relationship between cortex, cerebellum), attention to pain (dorsal contralateral depression and pain symptoms, as well as between pain and anterior, dorsolateral prefrontal cortex), emotional aspects suicidal thoughts. The patients with a long history of pain of pain (claustrum, closely connected to amygdala) and disorders also have an increase in depression and anxiety motor control [16]. Analysis of video records revealed that symptoms, and suicidal thoughts. Patients with more severe high pain catastrophizers displayed communicative pain depression and anxiety symptoms also have an increase of behaviours (e.g. facial displays, vocalizations) for a longer pain problems [6]. In a detailed metaanalysis by Bair et al. duration when an observer was present, compared to [7], the frequency of reporting pain complaints by patients high pain catastrophizers who were alone during the pain with depression ranged from 15–100%, mean value 65%. procedure. High pain catastrophizers show a propensity In the studies by Kirmayer et al. [8], among patients who to engage in strategies that more effectively communicate satisfied the criteria for depressive disorders according to their pain, and are less likely to engage in strategies that various self-assessment questionnaires, 75–80% of them might minimize pain [17]. Exclusively intrapsychic mentioned such pain complaints as: headaches, stomach conceptualizations of pain catastrophizing a maladaptive ache, neck and back pain, and non-specific pains. In the cognition (e.g. cognitive errors) seems to be incomplete. population of patients hospitalized due to severe depression, Similar to pain behaviour, pain catastrophizing is enhanced 92% reported at least one pain symptom, while 76% – many by the social context. A full understanding of the functions pain complaints. Nearly 60% of patients with depression and consequences of pain catastrophizing will require more reported pain at the moment of making the diagnosis [9]. attention to questions concerning communication goals, The presence of depressive disorders increased the risk of coping preference and coping efficacy, interpersonal needs, Ann Agric Environ Med. 2013; Special Issue 1 25 Rafał Gorczyca, Rafał Filip, Ewa Walczak. Psychological Aspects of Pain and the social reinforcement contingencies that influence Acute pain stimuli in healthy subjects cause a consistent how, and to whom pain will be expressed [17]. and reproducible activation of a set of brain regions. This activity pattern is labelled as acute nociceptive pain-related Pain behaviour. Pain behaviour and conditioned pain. A brain activity or, simply, as pain ‘neuro matrix’. Imaging patient who experiences pain after a sustained injury or a the brain’s physiological properties in chronic chest pain surgical procedure learns to assume a body position with (CBP) is more complicated than in acute pain. In contrast which he/she feels less pain, or to avoid certain movements to acute pain, chronic pain is characterized by the presence which intensify pain. Thus, a patient may avoid lying on a of ongoing pain, and chronic pain patient populations are specified side if this causes an intensification of pain, may by nature inhomogeneous, use diverse modes of drug and limp on one leg, because burdening of this leg causes pain. other types of therapy, and most chronic pains are comorbid These behaviours are rewarding — cause a decrease in pain, with other conditions [22]. Pain intensity for spontaneous and to the contrary – loading or irritation of the site of CBP and thermal pain are encoded in different brain regions. lesion leads to the occurrence or increase in pain — acts as Pain intensity for spontaneous pain of CBP is significantly a punishment. Verbal and behavioural manifestation of pain positively correlated with the medial prefrontal cortex may be additionally strengthened by the behaviours of people (mPFC; including rostral anterior cingulate) activity, which from the patient’s surroundings. Complaining, painful is known to be involved in negative emotions, response grimaces, changes in body posture, evoke in them concern conflict, and detection of unfavourable outcomes, especially and sympathy, and incline them to provide assistance. The in relation to the self. Pain intensity for thermal pain in both reactions of the environment act as a prize, secondarily CBP patients and normal subjects is best correlated with enhancing a patient’s pain behaviours, which leads to an right insula activity encoding nociceptive information [22]. increase in the intensity of the pain experienced. It has been Moreover, chronic pain can be considered a driving force confirmed that patients who receive a higher level of social that carves cortical anatomy and physiology, creating the support show simultaneously an increased level of pain chronic pain brain/mind state [21]. behaviours [27]. In one of the studies, the best predictor of the level of pain and the level of activity of patients with Methods and techniques of pain treatment. Cognitive chronic pain, was an increased concern of the spouse in and cognitive-behavioural methods and techniques of pain response to pain symptoms [19]. treatment are aimed at helping a patient not only to limit the level of the pain experienced, but also to support his/ Early life adversity. A history of early life adversity her own activity, optimism, self-esteem, sense of control (ELA) — rejection, neglect, physical or sexual abuse has and self-efficacy [23]. In a comprehensive review of these health-related consequences that persist beyond the initial techniques carried out by Siang-Yang Tan in 1988 [24], the maltreatment and into adulthood. A relationship between author presented experimental, as well as clinical studies ELA and the development of irritable bowel syndrome (IBS) with the use of these techniques in order to assess, in the light in adulthood has been described in clinical literature and of the results presented, their effectiveness in pain control. animal models. Childhood adversity is associated with abnormal glucocorticoid signalling within the hypothalamic- (A) Cognitive methods. pituitary-adrenal (HPA) axis, and the development of (1) Provision of preparatory information. The provision of functional pain disorders such as the IBS. IBS and many preparatory information about an impending event which adult psychopathologies are more frequently diagnosed in may be discomforting or painful has often been used as a women, and ovarian hormones have been shown to modulate psychological strategy for pain control. This usually aims pain sensitivity [20]. at altering an individual’s cognitive appraisal of such an event which is more benign so that the pain eventually Imaging of the human brain in chronic pain. The first modern experienced during or after the event would be minimized. non-invasive brain imaging techniques were introduced to the The preparatory information provided can be divided into study of humans in pain 20 years ago. This started the new two main types: procedural information about the objective field of studying the awake human brain in pain. To-date, the aspects of the upcoming event, and sensory information only tools available to study human chronic pain are clinical about the specific sensations an individual is likely to exams and psychological assessments. New techniques now experience during such an event. Comment. The efficacy of make it possible to study brain activity while enduring pain this method is questionable. and chronic pain. New techniques can extract information (2) Cognitive coping skills. The use of cognitive coping regarding anatomical, functional, metabolic and cognitive skills or strategies (e.g., distraction or attention diversion) properties of the brain during pain. Electrical signals of the for pain control has existed probably as long as people have brain can be monitored by EEG, or magnetoencephalography experienced pain, but only recently have such techniques (MEG), recording techniques, which provide very accurate been subjected to controlled, experimental investigations information about the timing of nociceptive information regarding their efficacy for attenuating laboratory as well transmission to the brain, albeit with poor spatial specificity. as clinical pain. Blood and metabolism signals provided by functional Turk has classified these various cognitive strategies into magnetic resonance imaging (fMRI) and PET are currently 6 main categories. the most popular means of examining the human brain in (a) Imaginative inattention — ignoring the pain by engaging general, and also specifically for pain, yet they have lower in imagery which is incompatible with the experience of painł temporal resolution than EEG, or MEG, but much better for example, imagining oneself enjoying a pleasant day at the spatial information. Currently, the technique most commonly beach, at a party or in the country. Comment. The number of used to study the human brain remains fMRI [21]. unequivocal studies showing that imaginative inattention was 26 Ann Agric Environ Med. 2013; Special Issue 1 Rafał Gorczyca, Rafał Filip, Ewa Walczak. Psychological Aspects of Pain more effective than control for increasing pain tolerance, or (3) Multifaceted cognitive-behavioural treatment regimens. decreasing subjective reports of pain intensity was 6, whereas Comment. The studies reviewed provide some support, 3 studies unequivocally showed it was only equal to control. albeit tentative, for the efficacy of multifaceted cognitive- (b) Imaginative transformation of pain — acknowledging behavioural treatment regimens for the control of clinical the noxious sensations but interpreting them as something pain, e.g. low back pain, ulcer pain and headaches. More other than pain, or minimizing them as trivial or unreal. controlled studies, especially with attention-placebo and no The number of unequivocal studies showing this strategy treatment control groups, are needed before more definite to be more effective than control was 3, and the number conclusions can be drawn. More studies which attempt unequivocally showing it only equal to control was also 3. to identify the necessary or sufficient components of such (c) Imaginative transformation of context — acknowledging combined, multifaceted treatment regimens are also needed. the noxious sensations but transforming or changing their (4) Stress-inoculation training. This method refers to a setting or contextł for example, picturing oneself as “James comprehensive cognitive-behavioural intervention with 3 Bond”, having been shot in a limb, driving a car down a main phases which has been used for the management not winding mountain road while being chased by enemy agents. only of pain but also anxiety and anger. Unlike approaches One unambiguous study showed this strategy to be only equal that impose a specific cognitive strategy on all subjects, the to control for increasing pain tolerance. skills oriented stress-inoculation training approach takes into (d) Attention diversion (external) — focusing attention on account and capitalizes on the multidimensional nature and the physical characteristics of the environment for example, marked individual differences of pain reactions by providing counting ceiling tiles, or studying articles of clothing. subjects with the choice of a variety of coping skills. The Comment. Only one study unequivocally showed this first phase of the training for pain control is an educational strategy to be more effective than control, while two studies phase in which subjects are provided with an explanatory clearly showed it to be no better than control. scheme or conceptual framework (e.g., the Melzack-Wall (e) Attention diversion (internal) — focusing attention gate control theory) for understanding pain experience. on self-generated (non-imagery produced) thoughts, for Next, is a rehearsal phase in which subjects are exposed to a examples undertaking mental arithmetic or compiling a variety of cognitive and u techniques for coping with pain, list of words of popular songs. Comment. One study clearly based on the conceptual framework (e.g., relaxation and showed this strategy to be more effective than control, but 3 deep breathing, distraction, imagery strategies and coping studies clearly showed it to be only equal to control. self-statements or “self-talk”). Subjects are allowed, however, (f) Somatization — focusing on the part of the body to choose the coping techniques they wish to employ. The receiving the intense stimuIation but in a detached manner; for final phase of training is an application phase in which example, analyzing the intense stimulation and sensations as subjects are given an opportunity to test their newly acquired if preparing to write a biology report. Comment. Four studies skills either by imagery-rehearsal and role-playing, or by unequivocally showed this strategy to be more effective than exposure to an actual pain stressor (e.g., cold pressor task). control, and none showed it to be equal to control. However, Comment. External validity of stress-inoculation training of these 4 studies, only one included an attention-placebo for the reduction of more severe acute or chronic clinical group. Hence, the efficacy of somatizatization for control of pain has not been established [24]. laboratory pain in the other studies could have been due to A systematic review and meta-analysis made by Morley “placebo” effects. et al. in 1999 recovered 33 papers from which 25 trials suitable for meta-analysis were identified [25]. The following methods (B) Cognitive-behavioural methods. of exerting a therapeutic effect were noted: 1) biofeedback; (1) Provision of preparatory information plus skills instructions 2) relaxation; 3) biofeedback and relaxation; 4) coping or training. skills training; 5) cognitive restructuring; 6) education/ Several studies have investigated the efficacy of a combined bibliotherapy. For the needs of methaanalysis the above- cognitive-behavioural intervention consisting of the provision mentioned methods were ordered within 8 domains of of preparation information plus behavioural or cognitive- treatment, without specifying which particular methods behavioural instructions for coping skills or training for and techniques were applied in individual domains. The clinical pain control, particularly during or after noxious list presented below contains the number and percentage of medical procedures. Comment. Combined interventions studies which comprised a given domain: consisting of preparatory information, plus coping skills instructions or training for the reduction of stress or anxiety –– pain experience 25 (100%); reactions during or after noxious medical procedures, are –– mood/affect 22 (88%); effective. However, the data for pain attenuation per se are –– cognitive coping and appraisal 17 (68%); not as convincing. –– behavioural activity 17 (68%); (2) Prepared childbirth techniques. Prepared childbirth –– biological 9 (36%); techniques are really a special category of combined –– social role functioning 19 (76%); interventions consisting of preparatory information (about –– use of health care system 3 (12%); the process of childbirth) and coping skills training. The –– miscellaneous 5 (20%). coping skills component usually includes training in deep breathing, relaxation and/or attention focusing (e.g., focusing Three domains, biological, use of health care system, attention on a spot on a wall or the ceiling). Comment. The and miscellaneous, have been sampled by very few trials, data from both laboratory and clinical studies on the whole, and therefore did not include metaanalysis computations. provide some support, though not unequivocal, for the value Comparison with alternative active treatments revealed that of such techniques for pain control. cognitive-behavioural treatments produced significantly Ann Agric Environ Med. 2013; Special Issue 1 27 Rafał Gorczyca, Rafał Filip, Ewa Walczak. Psychological Aspects of Pain greater changes for the domains of pain experience, cognitive 11. Magni G, Moreschi C, Rigatti-Luchini S, Merskey H. Prospective coping and appraisal (positive coping measures), and reduced study on the relationship between depressive symptoms and chronic musculoskeletal pain. Pain 1994; 56: 289–297. pain experience (behavioural expression of pain). Differences 12. Von Korff M, LeReshe L, Dworkin SF. First onset of common pain on the following domains were not significant; mood/affect symptoms: a perspective study of depression as a risk factor. Pain (depression and other, non-depression, measures), cognitive 1993; 55: 251–258. coping and appraisal (negative, e.g. catastrophization), and 13. Sullivan MJL, Stanish W, Waite H, Sullivan M, Tripp DA. Catastrophizing, pain, and disability in patients with soft-tissue social role functioning. The author concludes that active injuries. Pain 1998; 77(3): 253–260. psychological treatments based on the principle of cognitive 14. Jensen MP, Turner JA, Joan M. Romano JM, Karoly P. Coping with behavioural therapy are effective for treatment pain [25]. chronic pain a critical review of the literature. Pain 1991; 47: 249–283. 15. Lefebvre MF: Cognitive distortion and cognitive errors in depressed psychiatric and low back pain patients. Journal of Consulting and Clinical Psychology 1881; 49(4): 517–525. REFERENCES 16. Gracely RH, Geisser ME, Giesecke T, Grant MAB, Petzke F, Williams DA and Clauw DJ. Pain catastrophizing and neural responses to pain 1. http://www.iasp-pain.org/AM/Template.cfm?Section=Pain_ among persons with fibromyalgia. Brain 2004; 127: 835–843. Definitions#Pain (access: 09.02.2014). 17. Michael J.L Sullivan, Heather Adams, Maureen E Sullivan. 2. Melzack R, Wall PD. The challenge of pain. New York, Basic Books, Communicative dimensions of pain catastrophizing: social cueing 1982. effects on pain behaviour and coping. Pain 2004; 107(3): 220–226. 3. Dickenson AH. Gate Control Theory of pain stands the test of time. Br 18. Gil KM, Keefe EJ, Crisson JE, Van Dalfsen PJ. Social support and pain J Anaesth. 2002; 88; 6: 755–757. behavior. Pain 1987; 29: 207–219. 4. Jessica A Davis, Rebecca L Robinson, Trong Kim Le, and Jin Xie: 19. Flor H, Krens RD, Turk DC: The role of spouse reinforcement, Incidence and impact of pain conditions and comorbid illnesses. J Pain perceived pain, and activity levels of chronic pain patients. Journal of Res. 2011; 4: 331–345. http://www.ncbi.nlm.nih.gov/pmc/articles/ Psychosomatic Research 1987; 31: 251–259. PMC3215513/. 20. Chaloner A, Greenwood-Van Meerveld B. Early Life Adversity as a Risk 5. Zagari MJ, Mazonson PD, Longton WC. Pharmacoeconomics of Factor for Visceral Pain in Later Life: Importance of Sex Differences. chronic nonmalignant pain. Pharmacoeconomics. 1996; 10(4): 356–377. Front Neurosci. 2013; 7: 13. 6. Wasilewski D, Wojnar M, Chatizow J. Depresja a ból: ogólnopolskie 21. Apkarian AV: The brain in chronic pain: clinical implications. Pain badanie epidemiologiczne. Psychiatria Polska 2010; 44(3): 435–445. Manag. 2011; 1(6): 577–586. 7. Bair MJ, Robinson RL, Katon W, Kroenke K. Depression and pain 22. Baliki MN, Chialvo DR, Geha PY, et al. Chronic pain and the emotional comorbidity. Arch. Intern. Med. 2003; 163: 2433–2445. brain: specific brain activity associated with spontaneous fluctuations of 8. Kirmayer LJ, Robbins JM, Dworkind M, Yaffe MJ. Somatization and intensity of chronic back pain. J. Neurosci. 2006; 26(47): 12165–12173. the recognition of depression and anxiety in primary care. Am. J. 23. Turk D, Okifuji A. A cognitive-behavioral approach to pain Psychiatry 1993; 150: 734–741. management.1999. 9. Von Knorrig L, Perris C, Eisemann M, Eriksson U, Perris H. Pain as a 24. Siang-Yang Tan. Cognitive and Cognitive-Behavioral Methods for Pain symptom in depressive disorders. I: Relationship to diagnostic subgroup Control: A Selective Review. Pain 1982; 12: 201–228. and depressive symptomatology. Pain 1983; 15: 19–26. 25. Morley S, Eccleston Ch, Williams A. Systematic review and meta- 10. Leino P, Magni G. Depressive and distress symptoms as predictors analysis of randomized controlled trials of cognitive behaviour therapy of low back pain, neck-shoulder pain, and other musculoskeletal and behaviour therapy for chronic pain in adults, excluding headache. morbidity: a 10 years follow-up of metal industry employees. Pain Pain 1999; 80(1–2): 1–13. 1993; 53: 89–94.